Turned Art Object – #3 Fixing Reference Hole, Body Face Template & Turning 1st Body Face

Since the existing reference point is off just a little, I need to relocate it.  If it was way off, I could just drill a new hole but it’s so close if I try and drill it at the correct location the drill bit would just bend to follow the existing hole.  My way around that is to plug the existing hole then drill a new hole in the right place.  This starts by drill in a much larger hole than needed for the plug with a short stiff Fostner bit followed by drilling a medium size pilot larger than the center point of the brad point drill used for the final hole the plug will be glued into.  What’s shown in the left photo is the final plug hole drilled using the brad point drill.  This drill is used because with the medium size pilot hole the spurs at the edge of the bit guide it rather than the center point which now just spins in midair.  The right photo shows the plug cutter bit being used to make the plug.  

The top left photo has the plug just set into place.  The tail stock with a flat center is then used to press the plug the rest of the way in shown in the top right photo.  The bottom left photo is after the Fostner bit has drilled the face of the plug down flush with the bottom of the first drilled large hole and the bottom right photo is after the new reference hold has been drilled.  Not shown was using the point of the live center in the tail stock to make a dimple for the new reference hole.

These two photos show how the live center will fit into the new reference hole which is 1/64” smaller than the pointed tip (red arrow) for a tight fit.

With a new reference hole drilled the 2 ½” mounting recess for the 4-jaw chuck is drilled finishing this bit of repair work. 

Before starting to turn the body of the piece I printed out a full scale section of about ¾ of it then glued that to a thin piece of plywood.  That’s shown in the top photo.  Using the bandsaw the half pattern gets cut out.

Cleaning up the bandsawn edge is next which as you can see in the top photo is pretty rough.  This starts with a large diameter sanding drum shown the bottom photo.  It’s used for most of the piece but as one gets closer to the left end the diameter of the drum is bigger than the arc of the pattern so I have to shift to a smaller drum.

Consecutively smaller drums are used with the last little bit done using a small round file.  The final smoothing and fairing of the pattern is done with sandpaper.  The bottom photo shows the finished pattern edge.

Turning the face curve on the body is next but to help me in getting close to the finished profile some dimensions get added to the template.  They are ½” apart and give me the depth of the material that needs to be removed.  To use I lay out lines ½” apart on the face of the blank then cut a slot just a little short of the listed dimension.  The top drawing below shows the distances and the bottom has them cut into the blank.

When the blank gets turned down to the bottom of the reference slots the form starts to take shape as shown in the two photos below.  The shape shown is really just roughed out but most of the material is now removed and from here on it’s working with the template to get the profile right.

Once the profile gets 99% done the final shaping is made to the curved surface so it flows smoothly without any high or low spots using sandpaper.  The first of the two sides is now done and ready for the turquoise inlay to be added. 

Before I could start on the inlay, I got an email from a friend who asked if I was interested in some extra wood in the form of four 3-inch square maple bed rails that are about 100 years old he no longer had any use for.  Since it’s hard for me to turn down free material like that a visit to his shop got scheduled.  When I got there, he had some other planks most of which are rough sawn and a couple of inches or better thick all for the taking.  They include the maple bed rails plus a good amount of walnut, some chinkapin, big leaf maple, white oak and some very old rosewood planks.  They all did fit in the car with the seats down but it was a pretty full load and is really appreciated. 

Getting back to the project adding the turquoise inlay is next.  This starts by cutting a recess using a narrow parting tool.  The recess is a little over 1/16” deep and a little over ¼” wide with the red arrows indicating its edges.  As discussed before since I knew that the body turning was going to be taken in and out of the lathe and had to be in almost prefect registration for the various parts to fit together.  With the profile turned and the inlay recess added it now seemed like as good a time as any to see how well the remounting reference hole worked.  Fortunately, the planning and relocated reference hole worked as planned when remounted in the lathe everything was centered and the blank ran true.

Next Up – #4 Turquoise Inlay & Oak Insert Part 1

Turned Art Object – #2 Materials, Making the Blank & a Problem

Pulling the material out of my stock is next.  In the photo below the two short pieces on the left are oak, the two on the top right are 1 7/8” square leopardwood and the large piece on the right along with the long piece at the bottom is 1 7/8” thick cherry.

After measuring the long cherry piece, I thought that there was just enough to get the body out of it, if everything worked just perfectly.  The constraint is not the thickness but the width of the individual pieces.  The final design diameter is 12” and I want a 12 ¼” diameter blank to give me a 1/8” buffer around the edge, not a lot but enough.  To give me the maximum usable material a thin kerf saw blade is used.  The left photo below has the thin-kerf blade on the left and a regular kerf blade on the right.  Now it’s not a lot thinner but there are seven joints in the blank so every little bit helps.  To set the fence for the cut the minimum piece width is marked on the end of the board and the fence set so the body of the blade is centered between those two lines as shown in the right photo.  It’s important to use the body of the blade and not one of the teeth since the teeth have a left and right set to them.  With a careful centering of the blade body, I can get a matched set of pieces with thickness to a few thousands of an inch of each other.

The long boards now get cut to length using a stop block and the chop saw except for the outer two pieces because they don’t have to be as long as the others.  I did not cut them right away because I think there is almost enough to get them from the remainder of one of the long boards.  If they get cut from the last two blanks I would end up a couple of short waste pieces.  This will make more sense in the next photo.  To keep them in sequence the end of each board is lettered and numbered.

To see if the end pieces can be cut from a single piece the remainder of the parts get clamped together and a circle is drawn on them the size required for the blank.  I can then measure the length required for the outer pieces which lets me know if one piece is long enough for both or if I will need to cut one from each of the remaining blanks.  As it worked out one board cut in half was enough with just a little to spare.  The photo below shows the finished clamped dry fit assembly with the short outer pieces.

Gluing the pieces together is next.  The top photo shows the pieces turned ¼ so the glue face is up.  The short piece near the bottom of the photo is the end piece and won’t need glue since there are eight pieces and seven joints.  In the bottom photo the glue has been applied using a fingered rubber glue spreader set in the blue holder at the top.  You can see where the glue stops short on the last clamped piece because that’s where the short end piece goes.  Here I used a waterproof glue not because it’s waterproof but because the dried color is closer to aged cherry.

Once the glue cures the blank gets run through the thickness sander to flatten it along with cleaning up the top and bottom surfaces so it’s ready to be rough cut to size. 

Cutting a circle a ¼” larger than needed on the band saw is next.  Since it had been some time since I checked the squareness of the table to the blade, I took just a minute to do that using my small steel square.  The top left photo shows everything was good and square and the top right one is ready to start cutting.  The bottom photo has the blank cut round.

Drilling a small hole through the center of the blank using the drill press is next.  This will be used for registration when the blank gets reversed during turning.  With a small hole dead center, I can use the live center in the tail stock to get the blank’s axis dead on with the lathe’s axis and provide some extra support when turning.

Next is to drill a 2 ½” diameter recess in one face where the four jaw expanding chuck will go to hold the blank in place while turning.  The outer pencil line is the outside edge where the inlay will go and the inner line is the where the through hole will eventually go. 

With the mounting hole drilled mounting the blank in the lathe for a squareness test is next.  Below you can see a drive center on the left and the live center on the right both inserted into the small through reference hole.  In theory because the reference hole is square to the blank and used to align the blank to the lathe’s central axis it should spin smoothly with no wobble.  Good plan that didn’t work as well as I thought because when spun the blank wobbled about 3/32” side to side and that’s too much.  

To rectify getting the blank square with the lathe’s axis is first.  That can be done a couple of ways one of which is shown below using a dial indicator.  It’s attached to the lathe’s bed via a magnetic base then the contact point is set against the face of the blank shown below.  The blank is spun and the amount of wobble is read on the dial.  Squaring is an iterative process of finding the high and low points then tapping the high point toward the low side half the total wobble then repeating until the high/low difference is acceptable.  After the blank was square, I checked to see how far the reference hole was from the point of the live center and it was just a tiny bit off.  Some calculations showed that to get the 3/16” total wobble the reference hole only needed to be out of square by .4 degrees or .015”.  However, I still need an accurate reference point so when taking the blank in and out it can be set up square.

Next Up – Fixing Reference Hole, Body Face Template & Turning 1st Body Face

Turned Art Object – #1 The Start, Design & Material Selection

This is one of those projects that has no real functional use but is for only artistic expression.  I have been thinking about this piece for a few months and finally had a rough enough form in my head to draw it up with the 3D drawing package.   Below the left drawing is what I would call the first version.  It’s not the first iteration as there were about half a dozen or so rough attempts before this one emerged.  On the right is the same piece where I added some of the potential materials.

The next version on the left got two caps added to the ends of the body arc since the end of the arc looked unfinished to me.  To me they act to terminate the flow of the body arc.  Further refinement adding more definition and highlighting the joint between the cherry and blackwood is a thin band of inlayed turquoise.

In looking at the body arc group I decided that to add a little ridge to break the smooth curve across its face.  The red arrow points to the ridge’s location at the edge of the blackwood piece and the inset shows an enlarged view of the inner piece. 

To add some interest to the outer body arc I took a look at adding a thin maple spacer between the cherry pieces that will get glued together to make the piece.  The spacing is based on mathematical Fibonacci sequence.  To get the sequence to fit within the overall width required a bit of work using an Excel spreadsheet.  What I thought was a good idea ended up making the piece look a bit like a Zebra and was way too distracting so it got discarded.  It just goes to show not all ideas that sound good actually are.

With the front design looking pretty good I took a look from the top of just the body arc with the blackwood caps removed to see how that looked which is shown in the top photo.  The body looked a bit too thick and bulky so I narrowed the group by about ½ an inch to give me the bottom profile that looked a lot sleeker.

Changing the thickness of the body arc group required a resizing of the arc end caps which was easy to do.  However, that got me thinking that nearly everything in the whole piece is curved except for the caps so they got changed to follow the cross-sectional shape of the body arc.  They also get tapered from the center line of the top to its edge.  The renderings below show a front and top view along with an enlarged detail of the blackwood cap looking from the inside out.  The caps may undergo additional changes when I get to that point in the build as I am not sure if I want to curve the tops of the caps instead of putting a flat taper on them as now shown.

My choice for materials developed along with the drawings.  With cherry being one of my favorite woods to work with I decided to use it as the main material.  I wanted the inner part of the body arc and the caps to be a contrasting wood and I looked at both light and dark materials.  Black ended up looking the best due in part to its contrast to the turquoise inlay.  Since the availability of truly black wood is limited and very expensive an alternate was needed.  One that has worked well for me is either oak or cherry dyed with India Ink.  For this piece oak will be used because when dyed and finished the grain of the oak will still be visible whereas the cherry could end up looking like a piece of featureless plastic.  This leaves the center bowl and finial.  I wanted a figured wood for these pieces and selected leopardwood.  Based on these decisions I made a test piece out of cherry to see how the meeting of the body’s three materials (blackwood, turquoise and cherry) would look.  The photo below shows the progression from filling a saw kerf cut into the cherry test piece with turquoise for the band to the finished sample and I have to say the black is pretty featureless.  

With the design fairly well set the next step is to go through my stack of material and pull out the pieces that more or less will probably be needed that is unless I decide to change my mind part way through the build.

Next Up – Materials, Making the Blank & a Problem